An enclosed device and method for controlled freezing of cell cultures, especially eucaryotic cell cultures, contained in cell culture vials by means of a conventional freezer includes a container and top, a supporting grid and supporting grid base within the container for supporting the culture vials and a compatible liquid refrigerant in a volume of at least fifteen times the culture volume and at a level to totally immerse all of the cultures to be frozen. Compatible liquid refrigerants include the straight chain aliphatic alcohols, preferrably ethanol and methanol.